System for Decreasing Energy Usage of a Transparent LCD Display Case

ABSTRACT

An apparatus for controlling a backlight is disclosed. The apparatus includes a housing and door. A transparent liquid crystal display and associated backlight is positioned between front and rear glass panels of said door. A door sensor is positioned to detect if the door is open or shut, and a controller connected to the backlight and door sensor measures the amount of time that has passed between door openings and drives the backlight at various levels based upon the elapsed time.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of U.S. Provisional Application No. 62/061,950 filed Oct. 9, 2014.

TECHNICAL FIELD

Embodiments generally relate to systems for reducing the energy usage of transparent liquid crystal displays (LCD) within display cases.

BACKGROUND OF THE ART

Display cases are used in a number of different retail establishments for illustrating the products that are available for sale. In some instances these display cases may be coolers or freezers which are placed in grocery stores, convenience stores, gas stations, restaurants, or other retail establishments. In other instances these display cases may be non-refrigerated transparent containers used in a jewelry or watch store, bakery, deli, antique shop, sporting goods store, electronics store, or other retail establishments. While the design and appearance of the product itself does provide some point-of-sale (POS) advertising, it has been found that additional advertising at the POS can increase the awareness of a product and in turn create additional sales.

Most retail establishments already contain some POS advertising, and depending on the type of establishment the proprietor may want to limit the amount of ‘clutter’ in the retail area—resulting in a very limited space for additional POS advertising. It has now become desirable to utilize the transparent glass that is typically placed in display cases with additional POS advertising. Most notably, it has been considered that transparent LCDs may be positioned along with the transparent glass and could display additional advertising materials while still allowing a patron to view the products inside the display case.

SUMMARY OF THE EXEMPLARY EMBODIMENTS

An exemplary embodiment provides a system for reducing the energy usage of a transparent liquid crystal display by tracking the activity of the opening/closing of the door containing the transparent liquid crystal display.

The foregoing and other features and advantages of the present invention will be apparent from the following more detailed description of the particular embodiments, as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of an exemplary embodiment will be obtained from a reading of the following detailed description and the accompanying drawings wherein identical reference characters refer to identical parts and in which:

FIG. 1 is a perspective view of a refrigerated display case having a transparent LCD assembly.

FIG. 2 is a perspective view of the refrigerated display case of FIG. 1 where the door has been opened.

FIG. 3 is a perspective view of the refrigerated display case of FIG. 1 showing the cavity for electronic devices as well as the location of Detail A.

FIG. 4 is a front view of Detail A shown in FIG. 3.

FIG. 5 is a perspective view showing a lower mounting plate and various electronic devices.

FIG. 6 is a perspective view showing an upper mounting plate.

FIG. 7 is a block diagram for an exemplary embodiment of the electronic components within the door as well as the electronic components in the cavity below the door.

FIG. 8 is a screen shot of an exemplary user interface for operating a power saving mode.

FIG. 9 is a flow chart for an exemplary logic structure for operating the optional power saving mode.

FIG. 10 is a flow chart for another exemplary logic structure for operating the optional power saving mode.

FIG. 11 is an electrical schematic representation of an exemplary embodiment of the system for tracking and analyzing display case usage.

DETAILED DESCRIPTION

The invention is described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/ or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Embodiments of the invention are described herein with reference to illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

FIG. 1 is a perspective view of a refrigerated display case 50 having a transparent LCD 200. Generally, the display case includes a housing 105, to which a door frame assembly 100 is fastened. In this embodiment, a cavity 110 is provided below the door frame assembly 100 where various electronic devices 111 for operating the transparent LCD assembly 200 can be located.

FIG. 2 is a perspective view of the refrigerated display case of FIG. 1 where the door has been opened. The transparent LCD 200 is preferably sandwiched between a front glass 225 and rear glass 205. Also preferably sandwiched between the front and rear glass 225/205 is an upper plate 216 and a lower plate 215, each of which are preferably attached to the rear glass 225 such that heat from the plates can be conductively transferred to the rear glass 225 and removed by natural or forced convection.

In an exemplary embodiment, the upper and lower plates are preferably bonded to the rear glass 205 through adhesive transfer tape. An exemplary adhesive transfer tape for this purpose would be 468 MP, available commercially from 3M™ of St. Paul, Minn. www.3M.com/converter. In order to illuminate the transparent LCD 200, one or more printed circuit boards (PCBs) each containing a plurality of LEDs 217 is preferably in conductive thermal communication with either the upper, lower, or both plates. In this way, heat that is generated by the LEDs 217 can be transmitted to the PCB and eventually transferring to the rear glass 205 where the heat can dissipate through natural or forced convection.

The LEDs 217 may serve as a backlight for the transparent LCD 200 and may be arranged to direct light near or through the transparent LCD 200. A light guide may be used, but is not required. The light guide would preferably be placed between the transparent LCD 200 and the rear glass 205.

FIG. 3 is a perspective view of the refrigerated display case of FIG. 1 showing the cavity for electronic devices as well as the location of Detail A. Also shown in this figure is the temperature sensor 620 which is in electrical communication with the electronic devices 111.

FIG. 4 is a front view of Detail A shown in FIG. 3. Here, various electronic devices 111 are shown within the cavity 110, and would preferably include a CPU and a wireless transmitter/receiver. Also shown here is a door sensor 600 which is positioned to determine whether the door is currently open or not. The door sensor 600 is preferably in electrical communication with the CPU, which contains an electrical connection to either an internet or satellite network.

FIG. 5 is a perspective view showing a lower mounting plate 215 and various electronic devices 400 in electrical communication with the LCD 200 as well as the electronic devices 111.

As noted above, preferably the electronic devices 400 are in conductive thermal communication with the plate 215 which is preferably bonded to and in conductive thermal communication with the rear glass 205 so that heat generated by the electronic devices 400 can be removed. Similarly, FIG. 6 is a perspective view showing an upper mounting plate which can also be used to mount various electronic devices and is also preferably bonded to and in conductive thermal communication with the rear glass 205.

FIG. 7 is a block diagram for an exemplary embodiment of the electronic components 400 within the door as well as the electronic components 111 in the cavity 110 below the door. The antennas 115 can be cellular network antennas or can be Wi-Fi receiving devices. In some embodiments, the modem may be connected through a hard-wired internet connection rather than cellular or wireless. Preferably, the video signal from the media player is transmitted to the receiving board 117 through wireless communication, although this is not required. The modem may be configured to receive data and transmit said data to various components, such as the Nexus board 116. The data may include instructions for operation of the LEDs 217.

The Nexus board 116 and the Receiver board 117 each contain a wireless device for communicating back and forth between the two boards and can operate under any form of wireless networking technology, including but not limited to: WPAN, WLAN, a wireless mesh network, or GAN. Specifically regarding the architecture for a WLAN network, these could include but are not limited to stations, basic service set, extended service set, and a distribution system. Further regarding the types of wireless LANs, these could include but are not limited to peer-to-peer, bridge, and a wireless distribution system. Any form of general encryption method can be used with the exemplary embodiments herein.

The cooler base 700 preferably contains electrical circuitry to communicate various attributes of the cooler to the board 116. The cooler attributes that can be communicated include, but are not limited to: evaporator temperature, cooler temperature, door open/close status, energy saving mode status, compressor status, evaporator fan status, and defrost status. The board 116 can then transmit the cooler attributes to a remote user through the modem. The board 116 can also record and transmit various attributes of the board 116 as well as the media player. These attributes can include but are not limited to: video input status, video resolution, voltage/current, and board temperature.

The board 116 can also communicate several alarm conditions, including but not limited to: temperature sensor failures, receiver board 117 communication failures, invalid defrost temperature, defrost timeout, missed defrost cycle, high/low temp exceeded, invalid video input, and video input stalled.

The LEDs 217 may be arranged along the top and bottom edges of the transparent LCD 200. The LEDs may be electrically connected to the board 116.

FIG. 8 is a screen shot of an exemplary user interface for operating a power saving mode. The power saving mode can be ‘enabled’ or ‘disabled.’ The user can select a backlight reduction percent level 1, which provides the percentage of power reduction to the backlight when level 1 power saving is detected. In this example, the level 1 power reduction is 34% from the normal operation power level. The user can also select how long the door remains closed before initiating level 1 power saving. In this embodiment, level 1 power saving is initiated once the door has been closed for 300 seconds.

Additionally, the user can select a backlight reduction percent level 2, which provides the percentage of power reduction to the backlight when level 2 power saving is detected. In this example, the level 2 power reduction is 73% from the normal operation power level. The user can also select how long the door remains closed before initiating level 2 power saving. In this embodiment, level 2 power saving is initiated once the door has been closed for 1800 seconds.

FIG. 9 is a flow chart for an exemplary logic structure for operating the optional power saving mode. The system first checks the sensor 600 to determine if the door is open. If yes, the current time is stored as the Previous Opening time (PO) and the backlight is driven at full power. If the door is closed, the present time is compared to the PO to determine how much time has elapsed since the previous door opening. The elapsed time may then be compared against predetermined time periods. If the time elapsed is not greater than Time Level 1 (ex. 300 seconds), the backlight continues to be driven at full power. If the time elapsed is greater than Time Level 1, the system moves on to compare the time elapsed with Time Level 2 (ex. 1800 seconds). If the time elapsed is less than Time Level 2, the backlight is driven at reduced level 1 (ex. 34% of full power). If the time elapsed is greater than Time Level 2, the backlight is driven at reduced level 2 (ex. 73% of full power).

FIG. 10 is a flow chart for another exemplary logic structure for operating the optional power saving mode. The system preferably begins by driving the backlight at full power. Next, the sensor 600 is checked to determine if the door has gone from opened to closed. If not, the system continues to drive the backlight at full power and continues to monitor the sensor 600. If yes, the current time is stored as the Previous Opening time (PO) and the logic moves forward to determine how much time has elapsed since the PO. If the time elapsed is less than Time Level 1, the door sensor 600 is again checked and if the door is still closed the system will return to measure the elapsed time since the PO, if however the door has been opened the system will return to the start where the backlight is driven at full power.

If the time elapsed is greater than Time Level 1, the system then preferably compares the elapsed time since the PO and compares it to Time Level 2. If the elapsed time is less than Time Level 2, the backlight is preferably driven at Reduced Level 1. If the elapsed time is greater than Time Level 2, the backlight is preferably driven at Reduced Level 2. In either scenario the system will preferably again check the sensor 600 and if the door has been opened the system will return to the start where the backlight is driven at full power. If however the door remains closed, the system will preferably return to the logic step of comparing the elapsed time since the PO with Time Level 1.

FIG. 11 is an electrical schematic representation of an exemplary embodiment of the system for tracking and analyzing display case usage. Here, a plurality of display cases 50 are in communication with an internet/cellular network 70. Here, an operations center contains at least one CPU 40 which can communicate with the plurality of display cases 50 through the internet/cellular network 70.

The embodiments of the wireless communication and transparent LCD system described herein can be used with any number of display case designs, either temperature controlled or not, and with doors that open or glass that remains stationary. Although shown here with a transparent LCD, the wireless system could be used with a traditional backlit LCD as well.

Having shown and described a preferred embodiment of the invention, those skilled in the art will realize that many variations and modifications may be made to affect the described invention and still be within the scope of the claimed invention. Additionally, many of the elements indicated above may be altered or replaced by different elements which will provide the same result and fall within the spirit of the claimed invention. It is the intention, therefore, to limit the invention only as indicated by the scope of the claims. 

We claim:
 1. An apparatus for controlling a backlight comprising: a display case comprising a housing and a door, the door comprising front and rear glass panels; a transparent liquid crystal display and associated backlight positioned between the front and rear glass panels; a door sensor positioned to determine whether the door is open or closed; and a controller electrically connected to the backlight and door sensor, where the controller measures the amount of time that has passed between door openings and drives the backlight at various levels based upon time between openings.
 2. The apparatus of claim 1 further comprising: a modem electrically connected with said controller configured to receive backlight power reduction data for the backlight and transmit said backlight power reduction data to the controller.
 3. The apparatus of claim 2 further comprising: a media player electrically connected with the controller and configured to transmit content data to the liquid crystal display.
 4. The apparatus of claim 3 further comprising: a temperature controller electrically connected to the controller.
 5. The apparatus of claim 1 wherein the backlight comprises: a series of light emitting diodes located along an upper and lower edge of the liquid crystal display.
 6. The apparatus of claim 5 wherein: the controller comprises a nexus board.
 7. The apparatus of claim 6 wherein: the controller drives the backlight at normal operational power unless and until the amount of time that has passed between door openings and closing, as detected by the door sensor, reaches a predetermined threshold, then the controller drives the backlight at a reduced operational power according to the backlight power reduction data.
 8. The apparatus of claim 7 wherein: the controller drives the backlight at a second reduced operational power according to the backlight power reduction data if the amount of time that has passed between door openings and closings, as detected by the door sensor, reaches a second predetermined threshold.
 9. A method for controlling a backlight of a transparent liquid crystal display housed within a door of a display case and electrically connected to a controller comprising the steps of: determining if the door is closed; calculating the time elapsed since the door was closed; and operating the backlight at a predetermined power level according to the time elapsed.
 10. The method of claim 9 further comprising the step of: accepting data at the controller by way of a modem for operation of the backlight.
 11. The method of claim 10 wherein: the data comprises a first predetermined percentage of reduction level, a second predetermined percentage of reduction level, a first period of elapsed time, and a second period of elapsed time.
 12. The method of claim 9 wherein: the backlight is driven at zero percent reduction in power when the door is opened.
 13. The method of claim 11 wherein: the backlight power is reduced by the first predetermined percentage of reduction level if the first period of elapsed time is reached.
 14. The method of claim 11 wherein: the backlight power is reduced by the second predetermined percentage of reduction level if the second period of elapsed time is reached.
 15. The method of claim 11 wherein: the second predetermined percentage is greater than the first predetermined percentage; and the second period of elapsed time is greater than the first period of elapsed time.
 16. The method of claim 11 wherein: the data is provided by a remote user through the modem.
 17. A method for controlling a backlight of a liquid crystal display (LCD) located in a door of a display case and electrically connected with a modem comprising the steps of: accepting backlight data from the modem, said backlight data comprising a first reduced backlight level corresponding with a first time threshold, a second reduced backlight level corresponding with a second time threshold; operating the backlight at normal operation power level; recording the elapsed time following a closing of the door and driving the backlight at normal operation power level; operating the backlight at the first reduced backlight level if the elapsed time reaches a first time threshold; and operating the backlight at the second reduced backlight level if the elapsed time reaches a second time threshold
 18. The method of claim 17 wherein: the backlight is operated at the normal operation power level when the door is opened.
 19. The method of claim 18 wherein: the backlight is operated at the normal operation power level when the elapsed time has not reached the first predetermined time threshold.
 20. The method of claim 17 wherein: the first reduced backlight level is a higher luminance than the second reduced backlight level. 